This sounds good, but one day my grandson left a washable marker on a large white dish towel and it bled out on the towel. My daughter said not to worry it would come out. as soon as they left I washed it and it did not all come out, and as long as I had it you see a blue spot on it. Not to be a downer, You might want to try it on scraps first. You have so much work in quilts to have a spot on it. And yes it was a washable pen.